Could not parse the ephemeral key response following protocol - node.js

Question

I am trying to create an ephemeral key in my IOS app. I can successfully create a stripe customer that saves in my firebase console and on my stripe dashboard. However, when I try to create the ephemeral key, I am receiving the error in my ios console after trying to view the checkout controller.
'Could not parse the ephemeral key response following protocol STPCustomerEphemeralKeyProvider. Make sure your backend is sending the unmodified JSON of the ephemeral key to your app.
and on my firebase function logs I am seeing,
createEphemeralKey
Request has incorrect Content-Type.
createEphemeralKey
Invalid request, unable to process.
in my index.js file, the code that I am using is
exports.createEphemeralKey = functions.https.onCall(async(data, context) => {
var stripeVersion = data.api_version;
const customerId = data.customer_id;
return stripe.ephemeralKeys.create(
{customer: customerId},
{stripe_version: stripeVersion}
).then((key) => {
return key
}).catch((err) => {
console.log(err)
})
})
Below is how I create my stripe customer.
exports.createStripeCustomer = functions.auth.user().onCreate((user) => {
return stripe.customers.create({
email: user.email,
}).then((customer) => {
return admin.database().ref(`/stripe_customers/${user.uid}/customer_id`).set(customer.id);
});
});
and then myAPIClient looks like.
enum APIError: Error {
case unknown
var localizedDescription: String {
switch self {
case .unknown:
return "Unknown error"
}
}
}
static let sharedClient = MyAPIClient()
var baseURLString: String? = "https://myProject.cloudfunctions.net/"
var baseURL: URL {
if let urlString = self.baseURLString, let url = URL(string: urlString) {
return url
} else {
fatalError()
}
}
func createCustomerKey(withAPIVersion apiVersion: String, completion: #escaping STPJSONResponseCompletionBlock) {
let url = self.baseURL.appendingPathComponent("ephemeral_keys")
Alamofire.request(url, method: .post, parameters: [
"api_version": apiVersion,
])
.validate(statusCode: 200..<300)
.responseJSON { responseJSON in
switch responseJSON.result {
case .success(let json):
completion(json as? [String: AnyObject], nil)
case .failure(let error):
completion(nil, error)
}
}
}
On my checkOutVC, I have
var stripePublishableKey = "pk_test_testProjectKey"
var backendBaseURL: String? = "https://myProject.cloudfunctions.net"
let customerContext = STPCustomerContext(keyProvider: MyAPIClient())
init(price: Int, settings: Settings) {
if let stripePublishableKey = UserDefaults.standard.string(forKey: "StripePublishableKey") {
self.stripePublishableKey = stripePublishableKey
}
if let backendBaseURL = UserDefaults.standard.string(forKey: "StripeBackendBaseURL") {
self.backendBaseURL = backendBaseURL
}
let stripePublishableKey = self.stripePublishableKey
let backendBaseURL = self.backendBaseURL
assert(stripePublishableKey.hasPrefix("pk_"), "You must set your Stripe publishable key at the top of acceptWorker.swift to run this app.")
assert(backendBaseURL != nil, "You must set your backend base url at the top of acceptWorker.swift to run this app.")
Stripe.setDefaultPublishableKey(self.stripePublishableKey)
let config = STPPaymentConfiguration.shared()
config.appleMerchantIdentifier = self.appleMerchantID
config.companyName = self.companyName
config.requiredBillingAddressFields = settings.requiredBillingAddressFields
config.requiredShippingAddressFields = settings.requiredShippingAddressFields
config.shippingType = settings.shippingType
config.additionalPaymentOptions = settings.additionalPaymentOptions
config.cardScanningEnabled = true
self.country = settings.country
self.paymentCurrency = settings.currency
self.theme = settings.theme
MyAPIClient.sharedClient.baseURLString = self.backendBaseURL
let paymentContext = STPPaymentContext(customerContext: customerContext, configuration: config, theme: settings.theme)
self.paymentContext = STPPaymentContext(customerContext: customerContext)
super.init(nibName: nil, bundle: nil)
self.paymentContext.delegate = self
self.paymentContext.hostViewController = self
self.paymentContext.paymentAmount = 5000 // This is in cents, i.e. $50 USD
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
I apologize for the long lines of code but I am really running into a brick wall. Why isnt the backend creating the ephemeralKey for customers?

Answer 1

Two things are jumping out at me:
You’ve written a callable type function (using onCall) but you’re
trying to call it with a normal HTTP request. These functions need to
be called with Firebase’s client library
(https://firebase.google.com/docs/functions/callable#call_the_function).
This stack overflow answer provides some great links about this:
Firebase Cloud Function to delete user.
Your firebase function is parsing stripe_version and customer_id from
data, but your request is only sending api_version. Where in your
code are you sending stripe_version and customer_id?